newtype MapLog

Noticed that Semigroup instance of Map is not suitable to use
for MapLog. For example, it behaved like this:

ghci>  parseTrustLog "foo 1 timestamp=10\nfoo 2 timestamp=11" <> parseTrustLog "foo X timestamp=12"
fromList [(UUID "foo",LogEntry {changed = VectorClock 11s, value = SemiTrusted})]

Which was wrong, it lost the newer DeadTrusted value.

Luckily, nothing used that Semigroup when operating on a MapLog. And this
provides a safe instance.

Sponsored-by: Graham Spencer on Patreon

Command/Expire.hs

@@ -73,7 +73,7 @@ start (Expire expire) noact actlog descs u =
 					trustSet u DeadTrusted
 				next $ return True
   where
-	lastact = changed <$> M.lookup u actlog
+	lastact = changed <$> M.lookup u (fromMapLog actlog)
 	whenactive = case lastact of
 		Just (VectorClock c) -> do
 			d <- liftIO $ durationSince $ posixSecondsToUTCTime c